By Ron Hammond and Andy Michel, OSU Extension entomologists
We had reported the lack of eggs at most buckthorn sites last fall, but we did find lots of eggs on buckthorn at Mirror Lake on the OSU Campus in Columbus. We sampled these various sites over the past few weeks and did not find any aphids following the leafing-out of the buckthorn, including the Mirror Lake buckthorn where masses of eggs were found.
However, in looking at the eggs that were still there, it was observed that the eggs, while still present, were all shriveled. Having talked with people more in the know, these eggs were perhaps not fertilized last fall, maybe from a lack of males.
Based on these observations and past history, we predict that Ohio, and only speaking for Ohio, will experience a “low aphid” year. We expect aphids to be hard to find through most of the summer, and will only rise in numbers in late summer/early fall prior to migrating to buckthorn. In essence, we expect to continue the 2-year cycle of “high – low” aphid years, with 2012 being another low year. However, this cycle, because of unknown reasons, could change at any time. Thus, we urge you to continue to scout for this insect pest